At night, yellow over yellow lights are typically shown on which part of a vessel?

Yellow over yellow lights displayed at night indicate a specific situation for a vessel. When these lights are shown on the stern of a tugboat that is pushing ahead, they signal that the tug is engaged in a towing operation. This configuration helps to convey to other vessels in the vicinity that the tug, along with the tow, is on the move and indicates the orientation and handling characteristics of the vessel.

The presence of yellow lights in this context serves an important safety function; it lets other mariners know that they should exercise caution when navigating in the vicinity of the engaged vessel. Proper identification through lights is crucial for collision avoidance and effective maritime communication, especially at night when visibility can be limited.

Understanding the role of navigation lights, including their colors and positions, is essential for maintaining safety on the water, particularly during nighttime operations when distinguishing between different types of vessels and their actions becomes vital.